Arrangement for the closing ring of a floating roof for mineral oil tanks and tanks for similar products



2,839,216 ING R. A. M. SCHENCK ARRANGEMENT F June 17, 1958 O THE CLOSING RING OF A FLOAT ROOF FOR MINERAL OIL TANKS AND TANKS FOR sIMn. PRODUCTS 2 Sheets-Sheet 1 Filed April 26, 1956 June 17, 1958 Filed April 26, 1956 R. A. M. SCHENCK ARRANGEMENT FOR 2 THE CLOSING RING OF A FLOATIN ROOF FOR MINERAL OIL TANKS AND TANKS FOR SIMILAR PRODUCTS 2 Sheets-Sheet 2 ,e. A. MSG/7W, Ma i/W0? Pt mil-4L Arm/way:

United States Patent 2,839,216 Patented June 17, 1958 ARRANGEMENT FOR THE CLOSING RING OF A FLOATING ROOF FOR MINERAL OIL TANKS AND TANKS FOR SIMILAR PRODUCTS Robert Albert Maurice Schenck, Antwerp, Belgium Application April 26, 1956, Serial No. 580,824 Claims priority, application Belgium March 1, 1956 5 Claims. Cl. 220-26) The invention relates to an arrangement for the closing ring of a floating roof for tanks, particularly tanks for petroleum and the like products. Floating roofs of this kind must fulfil multiple seemingly contradictory requirements. Especially they must be capable of vertical movement, be adapted to yield in a supple manner to lateral load forces and within certain limits to sway whilst riding on the liquid mass, without impairment of the tightness.

For this purpose use is generally made of relatively complicated connecting means connecting the body of the floating roof with the closing ring, said known means being relatively costly.

The invention contemplates a novel arrangement which is relatively very simple and generally so conceived, that theradial pressure acting on the closing ring varies as the angle of the pressure varies.

Said variable pressure angle device is realized by the combination of hinged connecting means between the floating roof body and the closing ring, said connecting means being so designed that the radial pressure acting on said closing ring varies with the variations of the pressure angle due to relative movements between said closing ring and the floating roof body. Said connecting means mainly consist of suspension members fixed to the floating roof body or to the closing ring, said suspen sion members bearing on the edges of oblique, generally curved oblong slots, which are provided in wings or lips radially projecting from the: closing ring or from the floating roof body respectively. The shape and obliqueness ofv said guiding slots are duly determined according to specified minimum and maximum limits of the pressure actingon the closing ring. In general the average slope of said slots is about 45 f" or slightly greater than 45, but will in each case be determined in accordance with the variations contemplated for the horizontal pressure force. lithe dead .weight of the closing ring, including the elements fixed thereon, is supposed to be practically constant, and if the limits of the radial pressure to act on the closing ring have been fixed in consideration of practical conditions at one hand, and of the requirements for ensuring a specified tightness of the seal at the other hand, the resultant of the forces may be obtained, wherefrom it'is easy to determine, by computation and/or graphical representation, the position and the direction of the bearing surface elements of the cooperating hinge members interconnecting the floating roof body and the closing ring. By joining said bearing surface elements it is easy to trace the shape of the aforementioned oblong slots.

Thus the arrangement contemplated by the invention may be adapted to the different cases met with in practice.

Having declared the scope of the invention, a specific embodiment will hereinafter be described in detail with reference to the accompanying drawings, in which:

- Figurel shows a radial section through a floating roof providedwith an arrangementaccording to the invention;

Figure 2 shows a partial top view, the upper pliant ring being taken away;

Figure 3 represents on an enlarged scale, a partial radial section, showing particularly the hinged connecting device interconnecting the floating roof body and the closing ring;

Figure 4 is a diagram showing in the conventional way the variation of the horizontal pressure due to the variations of the pressure angle.

In the example shown in Figures 1-3, the closing ring is composed, in the well known way, of a plurality of ring portions 1, e. g. made of steel, normally applied against the inside of the tank 2 and mutually interconnected by means of vertical junction strips 3, e. g. made of synthetic rubber, in a way as to render said ring expansible. The upper and lower edges 45 of the ring portions 1 are preferably bent inwards. The variable pressure angle device constituting the hinged connection between the closing ring and the floating roof body has been realized as follows: each of the ring portions 1 comprises at least one pair of lips 7 projecting inwards from said ring portion; the roof body 6 comprises, in places correlated with each of said pairs of lips 7, at least one lip 8 projecting radially from said roof and provided with a sloping curved oblong slot 9. Said slots 9 each cooperate with a suspension element 10 fixed on the corresponding pair of lips 7 and passing through said slot. As shown schematically in Figure 4, the oblong slots 9 may easily be traced by starting from the practically constant dead weight V of the closing ring and from the average horizontal pressure force P and the minimum and maximum horizontal pressure forces P and P" respectively; said characteristic components determine the variable pressure angles B, a, 'y, acting on the closing ring as well as the corresponding resultant forces. Having determined the latter forces it is easy to establish the shape of said oblong slot 9. The width of the latter is generally substantially equal to the diameter of the supporting members 10. The upper edge of the ring portions 1 and the upper edge of the floating roof 6 are interconnected by an elastic ring 11 e. g. made of synthetic rubber.

The arrangement according to the invention, which is characterised by the variable pressure angle, operates as follows: normally the floating roof body 6 rests on the liquid mass contained in the tank 2; the closing ring tending to slide downwards by gravity along the inside 2 of said tank is suspended from the floating roof by means of the suspension members 10 passing through the oblong slots 9; the practically constant vertical force of gravity V is decomposed and gives rise to the horizontal component P which thus constitutes the normal pressure whereby the different portions 1 of the closing ring are forced against the corresponding parts of the tank in order to ensure that the latter is tightly sealed; if clue to any accidental cause e. g. due to lateral propulsion by the forces of the wind, the horizontal pressure P becomes, in the limiting condition, equal to P and P" respectively, the pressure angle will correspondingly be altered by the correlated movements of the floating roof, said pressure angle originally being equal to 3 and varying between the corresponding limits on and 'y.

Thus it is obtained that the horizontal pressure acting on the closing ring varies always in accordance with the pressure angle. Accordingly it is also ensured that the floating body is automatically centered whichever forces are acting upon it; that the closing ring is permanently forced with suflicient pressure against the inner face of the tank and finally that said closing ring will faithfully follow all movements of the floating roof body Without the tightness of the seal being impaired.

It will be understood that the example just described is by no means limitative and that it is possible, without departing from the scope of the invention, to modify even appreciably the shape, dimension and relative positions of the, various elements, which constitute the characteristic arrangement according to the invention.

The suspension members may either be fixedly connected with the closing ring or with the floating body, the oblong slots wherein said suspension elements rest being shaped and disposed correspondingly. Said oblong slots could of course be replaced by suitably shaped elements or any other arrangements, constituting similar devices, or enabling to obtain the same technical eflects, 1

as those previously described. Likewise, the closing ring could be realised in any other suitable way than the one described, and finally the guiding surfaces sustaining the support members may be either rectilinear or curved, while their slope may vary produced.

The invention relates to the device itself, as well as to the floating roof arrangements equipped with said device.

What I claim is:

1. Floating roof arrangement for a liquid storage tank, comprising a substantially flat body adapted to float on the surface of the liquid contained in said storage tank, an expansible ring arrangement adapted to be applied according to the forces to be variable pressure angle against the inner face of said storage tank so as to fit tightly all along'the periphery of said inner face, a

pluralityof lips fixed at spaced points on said ring arrangement, a plurality of radially disposed lips fixed at correlated peripheral points on said floating body, each of the second-mentioned lips having an elongated slot extending at an acute angle to the longitudinal vertical axis of the tank, and a separatesupporting member carried by each pair of the first-mentioned lips and extending through a separate slot, each interlinked pair of lips being adapted to transmit a force in a plane normal to the inner face of said storage tank, all of said lips extending in vertical planes, whereby the radial pressure acting on said ring arrangement varies in accordance with the angle of said force in said plane. Y

2. Floating roof. arrangement for a liquid storage tank, comprising a substantially flat body adapted tofloat' on the surface of the liquid contained in said storage tank 1 a'plurality of ring segments joined together by means of flexible strips to'form-an expansible ring arrangement adapted, to be applied against the inner face of said storage tank and to slide along the periphery of said inner face, a plurality .of pairs of lips projecting radially inwards from said ring arrangement at equidistant points along its periphery, a plurality of lips projecting radially outwards from said'floating body at correlated spaced points "along the periphery of said floating body, each of said outwardly projecting lips havingan elongated slot extending at an acute angle to the longitudinal vertical mentioned lip, whereby each of said inwards projecting,

pairs of lips of saidring arrangement is linked to a corresponding outwards projecting lip of said floating body,

' and whereby radial pressure acting on said ring arrangement VaI'lSS'lll accordance. with the angle of theifo'rce transmitted by said interlinked set of lips. V

3. Floating roof arrangement for a liquid storage tank, comprising a substantially flat body adapted to float on the surface of the liquid contained in said storage tank a plurality of ring segments joined together'flby m'eansj of flexible strips-to form an expansible ring arrangement adapted to be applied against the inner face of said storage tank so astofit tightly all along the, periphery ofsaid inner face, a pluralityof pairs of lips'projecting inwards from said ring arrangement riphery, each of said pairs of lips being provided with a suspension element, a plurality of lipsprojecting outwards from said floating'body at correlated spaced points along the periphery of said floating body, said outwards projecting lips each being provided with an elongated oblique curved slot through which extends the suspension element of the corresponding pair of inwards projecting lips of said ring arrangement, so as to restrict the relative movement between said floating body and said ring arrangement, all of said lips extendingin vertical planes, the shape and the slope of each said slot being so determined that the radial'pressure acting on said ring arrangement varies in accordance with the angle of the force transmitted by said suspension element engaged in said slot.

v 4. Floating roof arrangement for a liquid storage tank, comprising a substantially flat body floating on the surface of the liquid contained in said storage tank, a plurality of ring segments joined together by means offlexible strips to form an expansible ring arrangement applied against the inner face of said-storage tank so as to fit tightly all along the periphery of "said inner face,

a plurality of pairs of lips projecting inwards from said ring arrangement at spaced points along its periphery, each of said pairs of lips being provided with a suspension element, a plurality of lips projecting outwards from said floating body at correlated points along the periphery of said floating body, said outwards projecting lipseach comprising an elongated oblique circular slot receiving the suspension element of the corresponding pair of inwards projecting lips of said ring arrangement so as to restrict the relative" movement between said floating body and said ring arrangement, all of said lip s extending in vertical planes, the average slope of each said slot being about, but not less than 45 and being so determined that the radial pressure acting on said ring arrangement varies in accordance with theangl'e of the force transmitted by" said suspension element engaged in said slot. j" g 5. Floating roof arrangement for aliquid' storage tank, comprising a substantially flat cylindrical body floating centrally onthe surface of the liquid contained in said storage tank, a plurality of flexible ring segments made'of steel joined together-by means of vertical flexible strips made of synthetic rubber, to 'form, an expansible ring arrangement applied against the inner face of said storage tank so as to fit tightly all along the periphery of said inner face, the upper and lower edges of said ring segments being "bent inwards, 'a plurality of q I lips projecting inwards from said ring arrangement at spaced points along its periphery, each of said lips being provided with a suspension element, a plurality of lips projecting outwards fromthe" cylindrical surface of said floating body at correlated spaced points along said 'cylindrical periphery, said outwards projecting lips corresponding one. with each 'of said inwards projecting lips of said ring arrangement, said outwards projecting lips each comprisinga circular elongated slot'sloping'at about 45 and receiving the corresponding one of said suspension elements ofsaid inwards projecting. lips of said' ring arrangement, the width of said slot being 'substan tially equal to the diameter ofsaid corresponding suspension elementengaged 'in said slot, all of saidlips extending in vertical planes, and an annular membrane fixed between the upper edge of'said ring arrangement and the upper edge of said cylindrical'fioating body, said membrane being made of synthetic rubber.

References Cited in thefile offthis patent UNITED STATES, PATENTS 2,461,763 Oflfenhauser Feb. 15, 1949 2,464,804 Goldsby et a1. -Mar. 22,1949 2,587,508 Moyer et a1. "Feb: 26,1952:

at spaced points along its pe- Iddings. May- -10', 1927" 

